The outcome turned the ground-breaking super middleweight tournament upside down as Dirrell (19-1, 13 knockouts) beat the tournament leader and handed Abraham (31-1, 25) his first career loss.

But he had no chance to celebrate.

Well on his way to victory, Dirrell appeared to slip on some water in his opponent’s corner midway through the 11th round, and as he fell to a seated position, Abraham hit him on the left side of his head with a right.

Dirrell was down for several minutes while doctors examined him, and referee Laurence Cole waved the fight to an end at 1:13 of the round, awarding Dirrell the victory by virtue of an intentional foul.

At the time, Dirrell was ahead on all three judges’ cards, with Guido Cavalleri of Italy and Anek Hongtongkam of Thailand scoring it 97-92 and Michigan’s Frank Garza seeing it 98-91.

“Andre was creating a pretty painting and it’s like somebody came up and splashed something on it,” said Dirrell’s uncle and trainer, Leon Lawson Jr.

“He wanted to win it in the fashion he was winning in. He outclassed him, he beat him up, he was the stronger, faster fighter.

“Everything was beautiful. It was a perfect night, and the only hope he (Abraham) had was to do something as dirty as he did.”

Abraham denied he intentionally hit Dirrell while he was down, saying through an interpreter that he was only reacting as a boxer and that “You don’t wait until until your opponent has recovered.”

It was the second time Dirrell had slipped in Abraham’s corner, and Shaw claimed the Abraham camp was intentionally leaving water on the canvas.

In the confusion following the foul, as Dirrell lay prone on the mat, the ring filled with people from both camps. Among the first in the ring was his brother, Anthony, who ignored the referee’s demand to leave.

Andre eventually got to his feet, but by that time the fight was over.

“He was acting irrational even when he was sitting up,” said Shaw. “I knew we had to send him to the hospital.

“But he was most upset and crying when someone called him a coward. He wanted to finish the fight.”

The Abraham camp also wanted a urine test on Dirrell to check for steroids, a request Shaw regarded as an insult.

“I swear on my children and grandchildren that Andre Dirrell is not on drugs,” said Shaw.

At a venue named for Michigan’s greatest champion and just 75 miles from his hometown, Dirrell treated the partisan crowd to his greatest performance, taking command from the opening bell and knocking down Abraham in the fourth.

Chants of “USA, USA” grew louder through the fight, drowning out the cheers of the many flag-waving Armenians in the crowd.

By the seventh round, Abraham was bleeding from a cut on his right cheekbone that had to be examined by a doctor in the ninth.

During that pause, Andre Ward, Dirrell’s next opponent and his former Olympic teammate, turned toward press row and hollered, “Nobody’s invincible, baby. Nobody.”

Abraham, a former middlewight champ who defended that crown 10 times, had knocked out Jermaine Taylor in the first stage of the Super Six and was clearly the tourney favorite with three points.

Dirrell now has two points in the standings, which are bunched up by the upset. Abraham would have clinched a semifinal berth with a win.

Even if he doesn’t reach the semis, Dirrell still could win his first world championship by taking Ward’s WBA belt. That would foil the tournament’s aim of uniting two major titles. Carl Froch, who edged Dirrell in a split decision in October, holds the WBC belt.

Ward will fight Allan Green on June 19 in a bout that was postponed from April 24 by Ward’s knee injury.

Froch fights Mikkel Kessler on April 24.

RING NOTES — Ward was on hand to support his old Olympic teammate. Ward won gold and Dirrell took a bronze medal at the 2004 Games. They’ll fight for the first time in Stage 3.

“It’ll be a tough thing to do,” Ward said before Dirrell and Abraham got in the ring. “But he’s got a tough fight tonight to deal with and I’ve got a tough fight to deal with, so we’ll cross that bridge when we get there.”

Ward sees the Super Six format catching on in the boxing world.

“I think it clears up a lot of confusion and it’s great for the sport,” he said. “I’ve seen a lot of just mainstream sports fans get attracted by the Super Six, and as we get deeper into the tournament and crown a champion, I think a lot of people will pick up on it.

“I’d love to see this in any weight class. I think it’s going to be transcedent.” ...

Showtime laid out the tiebreakers in case two or more boxers share the fourth semifinal berth after the three group stages. The first tiebreaker is head-to-head competition, the second is total knockouts, and the third is total judes’ points accumulated in the three fights. ...